1. Field
Some embodiments relate to an optical device, and more particularly, an optical device configured to provide improved photo separation efficiency and a method of manufacturing the same.
2. Description of the Related Art
In some cases, an optical device includes photodetector which includes a two-dimensional (2D) material layer, including a transition metal dichalcogenide (TMD) layer. The TMD material layer may absorb light, and electrons and holes generated by the absorbed light may move out to electrodes at both sides of the TMD material layer. In some cases, a photo absorption rate associated with a photodetector varies depending on a thickness of the TMD material layer and the TMD material layer may be formed as a relatively thick layer, as light absorption of the TMD material layer may be improved with increased thickness of the TMD material layer.
However, as layer thickness increases, electrons and holes generated in the TMD material layer may, in a process of moving through the TMD material layer out to electrodes at both sides of the TMD material layer, disappear after recombination due to their falling down to a conduction band and a valence band of the TMD material layer. In some cases, the movement of the electrons and holes through the TMD material layer may be at least partially hindered due to defects existing in the TMD material layer. As a result, photo separation efficiency of the TMD material layer, and thus the optical device, may be reduced with increased thickness of the TMD material layer.